Safety device for article storage and retrieval apparatus

ABSTRACT

A safety device for assuring safe transport of article carrying containers positioned on carriers in a filing cabinet in which the carriers are moved in an orbital path. The cabinet is provided with an opening adjacent the orbital path of the carriers and a control system activates an appropriate drive mechanism to selectively position the containers for access thereto. The safety device locks and controls the locking of the containers on the carriers during transport.

United States Patent Lexe [ 1 SAFETY DEVICE FOR ARTICLE STORAGE AND RETRIEVAL APPARATUS [75] Inventor: Werner Franz Lexe, Worth,

Germany [73] Assignee: Sperry Rand Corporation, New

York, N.Y.

221 Filed: Mar. 2t, 1973 [21] Appl. No.: 343,293

[30] Foreign Application Priority Data Apr 19, 1972 Switzerland 5766/72 [52] US. Cl. 312/268 [51] Int. Cl A47b 49/00 [58] Field of Search 312/268, 23, 91, 97, 134, 312/135, DIG. 6, DIG. 29; 198/181 l l l l 1 1 1 [451 May 13, 1975 3,298,766 1/1967 Graber et a1 312/268 X 3,345,! 17 l0/l967 Goldammer et al. 312/268 3,464,750 9/1969 Anders 312/268 Primary ExaminerPaul R. Gilliam Assistant Examiner-Victor N. Sakran Attorney, Agent, or Firm-Griffin, Branigan and Butler [57] ABSTRACT 7 Claims, 3 Drawing Figures PATENTEB HAY I 31975 SHfEI 20? 2 SAFETY DEVICE FOR ARTICLE STORAGE AND RETRIEVAL APPARATUS BACKGROUND OF THE INVENTION The present invention concerns a device for locking and controlling the locking of containers or the like on carriers, during the transport in an article storage system, in particular in a filing cabinet with orbiting carriers.

On filing cabinets with orbiting carriers it is known to have these carriers designed in such a way, that they have on the side facing the access opening a threshold, and that means are provided to prevent putting the filing cabinet into operation when the container is not correctly placed on the carrier. This design has the disadvantage that prior to removing a container it must first be lifted before it can be pushed on the work table.

It is an object of the present invention to provide a device for locking and controlling the locking of containers or the like on carriers during the transport thereon, said device assuring an absolutely safe locking so as to avoid damages which could occur in operation of the filing cabinet when the container is shifted from its place on the carrier and is jammed.

BRIEF SUMMARY OF THE INVENTION The present invention contemplates a locking memher for each container, said locking member locking the container to the carrier during the transport in the article storage system, an unlocking member unlocking the locking member of the respective carrier prior to ejection of said carrier, and a sensing device for checking, after automatic or manual moving of the respective container onto the carrier, whether the locking member is locked with the carrier or not. The invention has the advantage, that it does not only provide a locking device, but also checks whether this locking device is locked. For this check, only a single sensing device is required even when the article storage system comprises a large number of carriers. This sensing device is stationary, so that it can easily be serviced, if such service should ever be necessary.

More specifically, the sensing device is a proximity switch. The proximity switch can check the position of the locking member with reference to the carrier. This check is made without touching. Present day positioning mechanisms for stopping the carriers at the access opening of an article storage system are so precise, that the carrier always stops in the region of a few millimeters. Therefore, it is sufficient to mount the proximity switch stationary on the frame of the machine, and to design the controls of the machine in such a way, that prior to actuating the motor a check is made as to whether the proximity switch has responded or not. If there is no response, the lock bar is not in locked position or it is too far away from the proximity switch, which can be easily checked.

It must be noted, that in this application a proximity switch is not simply the substitution of a normal switch. To the contrary, the application of a proximity switch provides substantial advantages by closing security gaps, which could not be closed easily in another way. As has already been explained, the proximity switch checks the position of the locking member with respect to the carrier. If the locking member is not in locked position, the proximity switch cannot respond. However, it would be possible, that the proximity switch is in locking position, but that the container is not fully inserted on the carrier, so that the locking member is not in a position to lock the container to the carrier. If this would not be recognized as a fault, there would be a security gap. The same is true for the other case, where the container is fully inserted, but the locking member is not in the locked position. A proximity switch is capable of recognizing both fault conditions. The proximity switch does not respond when the lock member is too far away, be it in vertical or horizontal direction, namely when the locking position is not reached, or when the container is not fully inserted on the carrier.

Still further the present invention contemplates that the locking member consists ofa lock bar suspended on a bell crank which is actuatable by the ejector mechanism for the container to lift the lock bar and to unlock the container from the carrier. This structure is very simple in design and very reliable in operationv BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematical cross-section through a filing cabinet with orbiting carriers and containers inserted therein.

FIG. 2 shows a view of a carrier from the back showing the locking member.

FIG. 3 shows a cross-section through the container and the carrier of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT As FIG. 1 shows, the carriers 1 of mechanized filing cabinets are usually suspended on endless chains 4 and are provided with a position stabilizing device 3 on both sides.

On each carrier I there is a container 7. By a key board, not shown, and a control device, also not shown, the mechanisms for driving the chains 4 can be so controlled, that each desired container 7 can be moved to the access opening 9. Then, an ejector device 11, which is preferably located behind the container, can push the container 7 to the work table 15 by means of a push arm 12.

According to the invention, the container is provided at the back with a locking member 17, the design of which can be seen at an enlarged scale in FIGS. 2 and 3. A sensing device consisting preferably ofa proximity switch 19 is provided to check the locking member of the container located on the carrier 1 by means of the ejector device 11 or by hand. The ejector device 11 serves not only for ejecting, but also for retracting the containers.

As FIGS. 2 and 3 show in particular, the locking member 17, located at the back wall 7a of the container, consists substantially of a bell crank 21, on which the lock bar 25 is supported by means of threads 23. The bell crank is rotatably supported by the brackets 27. A stop 29 serves to limit the motion in one sense of rotation. On the arm 35 of the bell crank is an actuating pin 37 on which the arm 12 of the ejector device can act.

A spring 39 biases the lock bar 25 in direction of locking. The lock bar is guided by the guide 41. A bevel 25a at the lock bar 25 allows to push the container or drawer also by hand onto the carrier and to lock it. By pushing in the drawer the lock bar 25 is lifted by the part In of the carrier 1 acting on the bevel 25a.

A sensing device consisting preferably of a proximity switch 19 is designed in such a way, that after moving the respective container 7 onto the carrier 1, it checks whether the locking member is in locked condition or not. If the lock bar 25, as shown in FIG. 2 or 3, is in its upper position, the proximity switch 19 cannot respond. The proximity switch 19 can also not respond when the drawer is not fully moved in, so that the distance between the lock bar 25 and the proximity switch 19 is too large.

Proximity switches responding to a sufficiently close object can today be obtained on the market as compo nents in different forms. They usually operate in that an electromagnetic resonance circuit is influenced by an object sufficiently close to the proximity switch or vice versa. They are relatively cheap, safe in operation and not easily influenced by environmental conditions. It would also be possible to use other devices acting as proximity switches, such as radiation detectors responding to radiation originating from or being reflected by the lock bar 25.

The device for locking and controlling the locking works as follows. On selection of the desired container 7, the article storage system moves the carrier 1 with the container 7 to the access opening 9. Preferably, positioning of the carrier 1 is controlled by a sensing means not shown, which respond to a mark on the carrier 1 so that this carrier can be positioned with great accuracy.

When the carrier has stopped, the ejector device 11 is operated, so that the arm 12 is moved against the container 7. Before the arm 12 abuts on the container wall 7a it contacts the pin 37 and moves the bell crank 21 in such a way, that the threads 23 lift the lock bar 25 against the bias of the spring 39, so that the arm 12 can move the container 7 to the table 15. The arm 12 is only schematically shown on the present embodiment. In reality the arm 12 is provided with magnets abutting on the container wall 7a, said magnets being active on a retracting motion to pull in the container 7.

When the container 7 is retracted, lock bar 25 can again move back into the position shown in FIG. 3. If, however, the container 7 should not be fully on the car rier l, proximity switch 19 cannot respond, because the distance to the lock bar is too large. Also when the container 7 is fully located on the carrier 1, but if the lock bar 25 has not moved to its lower position, the proximity switch 19 can also not respond. The control circuit is so designed, that only a response of the proximity switch 19 will enable the drive means for the chain 4 to be operated. In this way it is prevented that a container 7 not locked on the carrier is jammed in the machine and causes damage.

As has already been explained before, present day positioning mechanisms for stopping the carriers 1 at the access opening 9 of an article storage system are operated so accurately, that the carrier 1 is always stopped within a range of a few millimeters. However, if due to malfunction the carrier 1 would be stopped away from its normal stop position, also on normal function of the locking device, the proximity switch 19 on checking the locking, would not respond, because the lock bar 25 would not be in a position facing the proximity switch 19. If an addition to such a malfunction of positioning there would also be a malfunction of locking, one could imagine a condition, where the lock bar 25, when it is horizontally mounted, as shown in FIGS. 2 and 3, is located just opposite of the proximity switch 19, so that this proximity switch could respond in spite of the fact, that no locking took place. In order to prevent this, it is possible to arrange lock bar 25, or a member coupled to it and capable of being sensed by the proximity switch, in such a way, that the motion of the lock bar 25 or said member is transverse to the direction of motion of the carriers. In this case, positioning errors of the carrier could have no influence on the checking of the locking. However, experience has shown, that it is very easy to put the proximity switch 19 out of operation until the carrier reaches the normal stop position. In this way, it is avoided, that also on a wrong positioning the proximity switch will respond.

I claim:

1. A power operated article storage system comprising:

Endless carrier means carrying a plurality of carriers along an orbital path for selectively positioning the carriers at an access station;

A plurality of containers slideably supported on the carriers so that each container is slideable between a fully retracted position on the carrier and a later ally extended position from the carrier;

A plurality of locking assemblies each mounted on a respective container, said locking assemblies each including a movable locking member actuable for movement between a locking positin in which the movable locking member engages the container's carrier and thereby secures the container in the re tracted position to prevent relative sliding between the container and the carrier and an unlocked position in which the movable locking member is disengaged from the containers carrier and thereby permits relative sliding between the container and carrier, and further including a lock-actuating member operatively associated with said movable locking member for moving said movable locking member between said locking position and said unlocked position in response to activation of said lock-actuating member;

Container-sliding means positioned at the access station and operatively associated with a container positioned at the access station for sliding the container between the retracted and extended positions, said container-sliding means being aligned with the lock-actuating member of the container positioned at the access station so as to activate the lock-actutating member and thereby move its associated locking member from said locking position to said unlocked position prior to sliding the container from the retracted position to the extended position; and

Stationary sensing means positioned at the access station and aligned with the movable locking member of the container positioned at the access station for sensing the locking position of the movable locking member.

2. A power-operated article storage system as claimed in claim 1 wherein said stationary sensing means assumes a first state in response to said stationary sensing means sensing a container positioned at the access station in a fully retracted position and its movable locking member being in a locking position and assumes a second state in response to either the container being in a fully retracted position and its movable locking member being in an unlocked position or the container not being in a fully retracted position.

3. A power-operated article storage system as claimed in claim 2 wherein said stationary sensing means is a proximity switch.

4. A power-operated article storage system as claimed in claim 2 wherein said stationary sensing means includes a control means for deactivating said stationary sensing means under conditions where a carrier is not positioned accurately at said access station.

5. A power-operated article storage system as claimed in claim 1 wherein each of said locking assemblies comprises a lock bar suspended on a bell crank 

1. A power operated article storage system comprising: Endless carrier means carrYing a plurality of carriers along an orbital path for selectively positioning the carriers at an access station; A plurality of containers slideably supported on the carriers so that each container is slideable between a fully retracted position on the carrier and a laterally extended position from the carrier; A plurality of locking assemblies each mounted on a respective container, said locking assemblies each including a movable locking member actuable for movement between a locking positin in which the movable locking member engages the container''s carrier and thereby secures the container in the retracted position to prevent relative sliding between the container and the carrier and an unlocked position in which the movable locking member is disengaged from the container''s carrier and thereby permits relative sliding between the container and carrier, and further including a lock-actuating member operatively associated with said movable locking member for moving said movable locking member between said locking position and said unlocked position in response to activation of said lock-actuating member; Container-sliding means positioned at the access station and operatively associated with a container positioned at the access station for sliding the container between the retracted and extended positions, said container-sliding means being aligned with the lock-actuating member of the container positioned at the access station so as to activate the lockactutating member and thereby move its associated locking member from said locking position to said unlocked position prior to sliding the container from the retracted position to the extended position; and Stationary sensing means positioned at the access station and aligned with the movable locking member of the container positioned at the access station for sensing the locking position of the movable locking member.
 2. A power-operated article storage system as claimed in claim 1 wherein said stationary sensing means assumes a first state in response to said stationary sensing means sensing a container positioned at the access station in a fully retracted position and its movable locking member being in a locking position and assumes a second state in response to either the container being in a fully retracted position and its movable locking member being in an unlocked position or the container not being in a fully retracted position.
 3. A power-operated article storage system as claimed in claim 2 wherein said stationary sensing means is a proximity switch.
 4. A power-operated article storage system as claimed in claim 2 wherein said stationary sensing means includes a control means for deactivating said stationary sensing means under conditions where a carrier is not positioned accurately at said access station.
 5. A power-operated article storage system as claimed in claim 1 wherein each of said locking assemblies comprises a lock bar suspended on a bell crank actuatable by said container-sliding means to lift the lock bar and unlock the container from the carrier.
 6. A power-operated article storage system as claimed in claim 5 wherein said carrier includes a transverse flange element and said lock bar comprises on its front side, a bevel adapted to engage said flange to enable the manual insertion of the container onto the carrier.
 7. A power-operated article storage system as claimed in claim 1 wherein said stationary sensing means is a proximity switch. 